St. Croix bridge barges cleared for work, after mussels found

This view of the proposed St. Croix River bridge shows the bridge as it approaches the Wisconsin bluff. (Courtesy to Pioneer Press: Minnesota Department of Transportation)

Barges sidelined from work on the new St. Croix River bridge near Stillwater because of a zebra mussel scare have been cleared after the project's contractor submitted tightened decontamination controls to the Minnesota Department of Transportation.

Meanwhile, the state Department of Natural Resources is trying to identify three truck drivers who transported the barges from Wisconsin. Those drivers will receive $500 civil fines for transporting the invasive mollusks.

Transporting invasive species is against Minnesota law.

The mussels, found on the hulls of six of eight barges hauled to the river two weeks ago, were dead, and a MnDOT inspector spotted the mussels in a final check before the barges reached the river.

The zebra mussel shown is attached to a native mussel found in the St. Croix River. (Pioneer Press file photo)

"We had a failsafe in place and it worked," said Kevin Gutknecht, a MnDOT spokesman.

But the mussels should have been spotted sooner, he said.

The contractor, Edward Kramer and Sons, reviewed its decontamination plans and "made sure everybody knew who was accountable" for keeping the barges clean, Gutknecht said.

He said it's not clear where the decontamination process broke down the first time.

Work on the bridge wasn't held up by the mussels, he said.

The DNR plans to fine the truckers who hauled the barges, which came from the Milwaukee River and Fox River in Wisconsin.

Chris Niskanen, a Minnesota DNR spokesman, said the truckers should have made sure the barges were clean before transporting them.

"The real problem here began when these barges were taken out of the river in Wisconsin," he said. "You should be working with your contractor to make sure when those barges are being taken out of the water, they're going through a complete decontamination program."

The truck drivers work for two Wisconsin firms. The DNR doesn't yet know who the individual drivers were, and doesn't plan to pursue additional fines against the firms, Niskanen said.

He said the incident should be a reminder to all boaters to decontaminate their equipment, large or small, when leaving the water.

"This is the time of year when a lot of people are moving equipment," he said. "Everybody has to follow the law, from individuals to large companies."